The value of PET-CT scan in determining remission status in lymphoma patients involving the head & neck region

• Main Authors: Wan Fariza Wan Jamaludin, Fara Rahidah Husin, Aini Ab. Aziz, Mohd Razif Mohd Yunus, Mawaddah Azman, Kong, Min Han, Noraidah Masir, Mahdieh Ghoddoosi, Seery Zaliza Azura Zaider, Normi Mustapha, Nor Asiah Muhamad, S Fadilah Abdul Wahid
• Format: Article
• Language: English
• Published: Penerbit Universiti Kebangsaan Malaysia 2019
• Online Access: http://journalarticle.ukm.my/14405/1/20%20Wan%20Fariza%20Wan%20Jamaludin.pdf; http://journalarticle.ukm.my/14405/; http://www.ukm.my/jsm/malay_journals/jilid48bil10_2019/KandunganJilid48Bil10_2019.htm
• Institution: Universiti Kebangsaan Malaysia

In lymphoma, Positron Emission Tomography-Computerized Tomography (PET-CT) provides greater prognostic information than conventional imaging. However, false positivity occurred particularly in the head & neck due to predilection for infection and inflammation. We investigated the association between positive scans in the head & neck at the end of therapy with histology, and its diagnostic and prognostic values. 488 PET-CT were retrospectively assessed in 2012-2016 (40 months). Positive uptakes in the head & neck (five-point scale ≥4) were biopsied. Prevalence of positive scans was 10.9% (53/488). Two positive scans were histologically lymphomatous with mean maximum standardized uptake value (SUVmax) of 9.0±2.69. False positivity (96.2%) was histologically attributed to reactive lymphoid hyperplasia (SUVmax 9.0±3.88). Positive and negative predictive values, sensitivity and specificity were 3.8%, 100%, 100% and 89.5%, respectively. False positivity was associated with age, gender, extra-nodal involvement, Eastern Cooperative Oncology Group score (ECOG), positivity only in the head & neck and its pattern of positivity. No significant predictors were identified. Hodgkin Disease (HD) was more likely to have positivity only in the head & neck compared to Non-Hodgkin Lymphoma (NHL) (p=0.019). 106 patients with negative scans remained negative during study period, hence regarded as true negatives. Positive scans in the head & neck at post therapy yielded high false positivity and should not be routinely performed. HD has higher likelihood of scan positivity only in the head & neck than NHL. The value of PET-CT to detect true lymphomatous relapse in selected high-risk patients remained to be confirmed in future trials.